Most studies will set the environmental conditions (temperature, humidity, airflow) to mimic typical office and home environments (68 to 72F and 20 to 50%). For condition change studies, the chamber will operate between 65 and 85F and 25% and 80% RH with air flow turned off or set to a maximum of 3-4 m/s. For this type of study we will have the subject acclimate to a set of environmental conditions (approximately 20 minutes) and take a set of measurements. Then we will change the conditions (rate of change is 3F/hour and 3% RH/hour), have the subject acclimate to these conditions (later on the same day or on another day) and take another set of measurements. The expected study length is approximately two hours for a single visit.